A reclassification of the right anterior lobe of liver based on the anatomy of portal vein

Objective To evaluate anatomic features of intrahepatic portal and hepatic veins of right anterior lobe of liver,and provide a new concept of the classification of hepatic segment for imaging diagnosis and liver surgery.Methods The data from successive section MRI of the upper abdomen from 60 living donors for liver transplantation and three-dimensional images of 10 patients were used in this study.The course and division pattern of the intrahepatic portal and hepatic veins,and their relationships were investigated.Results The intrahepatic portal veins of eight hepatic segments can be mainly divided into ventral and dorsal branches,despite four branches could be found in some cases.About 90% dorsal branches supplied the dorsocranial area of the right lobe posterior to the right hepatic vein.Most branches of P5 gave off the right anterior trunk of P8v,and most drainage veins of S5 joined MHV.Therefore,the right anterior lobe could be divided into S8v+S5(ventral segment) and S8d(dorsal segment). Conclusions This new concept of hepatic segment division will be helpful for the accurate allocation of lesion in the liver,as well for the development of the new and safe surgical procedures.